Ion Mobility Spectrometry (“IMS”) is an analytical technique commonly used in searching for explosives, narcotics, and other trace contraband. As a result, IMS systems need to distinguish between closely-related chemical compounds and reliably respond when an illicit material is present. However, IMS systems typically have a lower resolution when compared to mass spectrometry (“MS”) or chromatography.
Hybrid ion mobility-mass spectrometry systems (“IMMS”) having an ion mobility spectrometer coupled to a mass spectrometer can have higher resolutions than conventional IMS systems. However, field-portable IMS systems require a small instrument footprint. As a result, mass spectrometers with bulky vacuum systems are not feasible for such an application. Accordingly, there is a need to improve the ability of field-portable IMS systems to resolve closely related chemical compounds.